Electrical coil and a method of making such



Jan. 25, 1949.

R. E. POWELL ELECTRIGAL COIL AND A METHOD OF MAKING SUCH Filed Jan. 11, 1945 l/VVE/VTO/q RE. POWELL 8y 8- u W. ATTORNEY heated article.

Patented Jan. 25, 1949 UNITED STATES PATENT OFFICE ELECTRICAL COIL AND A'METHOD'OF MAKING SUCH Raymond E. 'Powe'll, Westfield, "N. J., assigncr to Western "Electric Comp any, Incorporated, Nee. corporation of New York Application January 11, 1945, Serial No. 572,354 3 Claims. (Cl. 219- 13) This invention relates a method of making such, and more particularly or conduction from the Hence such coils may be constructed to have or be cross-sectioned a relatively heavy current- An object of the vide a simple method of making from suitably conductive material, which need not necessarily be ductile, an electrical coil to carry a heavy present invention is to pro- :steps of forming a chamber in eration, the substance of which need not necessarily be ductile.

With the abcveand other objects in view, the invention may be embodied making an integral angularly helical electrically conductive member tric'ally conductive material, and forming three plane slots in the body'all intersecting the chamco-planar,

originally a solid :rectangularly parellelo circual block of copper or graphite or other suitable electrically conductive material. As hereinafter explained, the material of the coil is not necessarily restricted to be ductile, since the coil is vertical bore I4 is drilled the rear andright end faces of the block opening The "counterbored as at '15 in its upper portion to receive a metal tube is conductively secured therein. A horizontal bore I1 is drilled in from atheright'end face near and parallel to the rearan'dbottom faces of the block, intersecting the bore H-at its bottom, and extending 'leftwardly shown in Fig. 3. A

to within a small distance short of the midlength of the block. The outer end of the bore I1 is counterbored a short distance to receive a closure cap l8 secured therein by any suitable means such as press fitting, soldering or screw threaded engagement. A bore I9 is drilled from the top surface vertically down near and parallel to the rear wall, a little to the right of the midlength of the block, down near to, but not through the bottom face of the block, and intersecting the bore I! at the inner end thereof. The outer end of the bore i9 is closed with a cap 20. From the rear face of the block near and parallel to the top face, parallel to the right end face, and near the midlength of the block, a bore 2| is drilled horizontally forward front face of the block, intersecting the bore |9 near its upper end, and is closed with a cap 22. From the right end face of the block, a bore 23 is drilled horizontally near and parallel to the top and front faces of the block, ending near and short of the midlength of the block and intersecting the bore 2|, the outer end of the bore 23 being capped at 24. A vertical bore 25, capped at 26, intersects the bore 23 near the right end of the latter and extends downwardly, near and parallel to the right end face and the front end of the front face of the block, nearly down to, but not through the bottom face of the block. A horizontal bore the right end face of the block near and parallel to the front and bottom faces of the block and intersecting the bore 25 nearly to, but not through the left end face of the block.

If the bores I4, ll, l9, 2|, 23, 25 and 21 be traced out in succession, it will be found that they form a continuous, rectangularly helical passageway of one and a quarter turns lying wholly within the right hand half of the body The chamber H is a horizontal bore drilled through the block from front to back with its axis in the axis of the helical passageway.

A slot is cut in the body of the block transversely across the block at itsmidlength from the top down to about the middle and from the rear face forward to about the middle leaving the right and left hand halves of the block integrally connected, as best shown in Fig. 4, over only the lower front quarter of the vertical central front to back cross section. A parallel slot 3|, midway between the slot 30 and the right end face of the block extends downwardly from the top face of the block into the chamber over the rear half ofthe front to back dimension of the block. A slot 32 parallel to the front and rear vertical faces of the block and midway between them divides the front half of the right half of the block from the corresponding rear portion over all but the left upper quarter thereofas best horizontal slot 33 extends from the chamber Hi to the chamber H and half way back through the block from the front face.

If now the one and a quarter turn helical passageway of the bores I4, l1, l9, 2|, 23, 25 and 21 be again traced out, it will be found that each bore is in an axis of a generally rectangularly parallelopipedal segment, representing each a one sixteenth section of the block, the eight of these in this half block being integrally connected in a one and a quarter turn helix containing the .passageway. Thus there is created, by the simplest of machining operations, a one and a quarter turn helical coil of massive construction whose conductive elements and cooling fluid pas- 21, capped at 28, extends fromtoward, but not through the straight planing or sawing.

bore 21.

be all omitted except such as are sageway are both adequate for the heaviest of loads.

The other half of the structure shown need not be described in detail since it is a mirror image duplicate of that described above.

Obviously, if only a single-chambered single coil is desired, only half the original block will be used, the slot 30 then representing one end wall and the terminal tube 34 being inserted into the Also, it seems too obvious to need detailed description or illustration that the same general method of boring and slotting can be extended if desired to lengthen the coil by additional fractional or whole turns, while still keeping the advantage of needing only the simplest of machining operations, straight drilling and Furthermore, as variously and incidentally noted above, the method herein disclosed makes it possible to make a water cooled coil for inductive or high frequency electric heating out of nonductile conductive material such as block carbon or graphite.

It may be desirable in some instances to make a coil of nonductile conductive material where it is not necessary to provide for the use of cooling the drilling operations may necessary to form the chambers Hi and H and, if necessary, to provide for connecting terminal members such as It and 34.

Considering the right hand half only of the duplex article disclosed, this being the simplest unit constructible in accordance with the invention, it is to be noted that the slot 32 extends half way up from the bottom and also half way in from. the right end of the cubical body about the chamber II, and intersects the periphery of the bodyhalf way down the left side, all along the bottom, all up the right side, and half across the top face, thus extending through three quarters of the periphery of the body in its plane. Were the plane of the slot 3| tilted to the left, the slot 32 would cut more than three quarters of the circumference of the body. Evidently the outer shape of the body need not be rectangularly parallelopipedal, nor do the planes of the slots 3|, 32 and 33, nor the axes of the bores l1, it, etc. need to be mutually at exact right angles, for the application of the invention. These directions and the outer shape of the body may be variously skewed and modified without departing from the spirit of the invention or from the scope of the appended claims.

I claim;

1. The method of making an integral angularly helical electrically conductive member which method comprises steps of forming in a body of electrically conductive material and having a chamber therein, a plane slot intersecting the chamber and intersecting more than half the periphery of the body in the plane of the slot, forming in the body a second plane slot meeting and communicating with the first named slot at a relatively large angle thereto and communi eating with the chamber, and forming in the body a third plane slot at a relatively large angle to each of the first named and second named slots and communicating with the first named slot and with the chamber, the three slots and the chamberbeing so disposed and proportioned that the substance of the body is thereby divided into integrally united segments in an angularly helically aligned sequence coiled about the chamber. 7 2. The method of making an integral angularly helical electrically conductive member which iluid. In such case,

m thod compr ses steps of o m n a chamber in large angle to each of the first named and seea body of electrically conductive material, and d amed lot and communicating with the forming three plane slots in h body all interfirst named slot and with the chamber, the three seating the chamber and no two slots being slots and the chamber being so disposed and propareli l or o-pianar, th three slots and the 5 portioned that the substance of the body is therechamber bein so dispos d and proportioned that by divided into integrally united segments in an the substance of the body is th r divided inte angularly helically aligned sequence coiled about integrally united segments in an angularly helit chambe1 cally aligned sequence coiled about the chamber. 6 A integral angulafly h li a nd tive 3. The method of making an integral angular- 10 member comprising a body 0f decfirjcally Com 5 helical electrica y conductive member which ductive material having a chamber therein and method comprises steps of forming in a b dy of formed with three plane slots in the body all inelectrically conductive material and having a tersecting the chamber and no two slots being chamber therein, a plane slot intersecting the parallel or 1 th t r slots and the chamber and interse t o e than half the 1f chamber being so disposed and proportioned that eat g W th he a o m in e body a member comprising a body of electrically conthird plane slot at a relatively large angle to each ductive material having a chamber therein and of the first named and nd named Slots and formed with a plane slot therein intersecting the communicating with the firs named S101? and chamber and intersecting more than half the pevvitn the chamber, the three slots and the chamriphery of the body in the plane of the slot, and

ber being so disposed and proportioned that the the body being formed with a second plane s ot substance of the body is thereby divided into inmeeting and communicating with the first named tegrally united segm nts in an angularly hcl slot at a relatively lar e angle thereto and com ly aligned sequence coiled about the chamber, in municatjng Wlth t Chamber, and t body combination with steps of forming in the succesm formed Wlth a thud m 1 1; t a relatively sive m m s f t sequence of Segments large angle to each of the first named and secfirst and last in the urf e f m Whieh it Was by divided into integrally imited segments in an ously communicating passageway along the anthe chamber, and each segment being ioimed eula iy axial line f t singularly helical with a straight bore therein intersecting the bore quence of segments. in the next adjacent segment near one end 4. The method of making an integral aneu1 r thereof, the successive bores forming a continuly helical electrically conductive member which usly communicating passageway along the an in the surface from which it was boied, the suc sive bores forming a continuously commun1cat cessive bor s forming a continuously communiing passageway along the angularly axial line of cating passageway along the angularly axial line the angularly helical sequence of segments. of the angularly helical sequence of segments. RAYMOND E. POWELL.

An integral angularly helical conductive member comprising a body of electrically con- REFERENCES ductive material having a chamber therein and The following references are of record in the formed with a plane slot therein intersecting the file of this patent: chamber and intersecting more than half the periphery of the body in the plane of the slot, and UNITED STATES PATENTS the body being formed with a second plane slot Number Name Date meeting and communicating with the first named 2,249,909 Pjsare July 22 9 slot at a relatively large an le thereto and com- 5 7 somes Sept. 2 1941 municating with the chamber, and the body be- 7 2 33 7 Gotha 13, 9 5

mg formed with a third plane slot at a relatively 2,391,222 Blattner Dec. 18, 1945 

